The present invention broadly relates to embroidering machines and the like and, more specifically, pertains to a new and improved method of operation and apparatus for an embroidering station having schiffli-shuttles and means for individual, group and/or repeat change of the schiffli-shuttles of embroidering, quilting and sewing machines and the like having shuttles.
Generally speaking, the method of the present invention is intended for operating shuttle machines, such as shuttle embroidering, quilting or sewing machines and the like, for selectively effecting individual, group and repeat changing of schiffli-shuttles in schiffli-shuttle embroidering stations.
The apparatus of the present invention is intended for changing shuttles of schiffli-shuttle embroidering stations in a shuttle machine, such as a shuttle embroidering, quilting or sewing machine and the like, individually, in groups or in repeats.
Individual, group and/or repeat change is an essential feature of the embroidering and/or design-making process. Whereas individual changing must be able to be carried out at any one of the embroidering stations, group and/or repeat change requires carrying out a predetermined sequence of activities while the machine is idle, which causes considerable productivity loss. In contradistinction to the needle side of an embroidering machine, the opposite or shuttle side operates with schiffli-shuttles, which in their interior space have an expendable schiffli-shuttle thread for fixing or tying the needle thread. After an average of eight hours, all schiffli-shuttles of such embroidering machines must be exchanged for newly loaded schiffli-shuttles. Depending upon the repeat configuration, the loss of production due to machine idle time, even when using a number of workers, amounts to 10% to 20% of the machine capacity. This machine idle time varies according to the design to be embroidered by the amount required for embroidering a new repeat configuration.
If, for instance, embroidering is initially performed with the least lateral spacing between two adjacent schiffli-shuttles equal to 4/4 (French inch=27.07 mm or 1.065 Imperial inches), and the design to be embroidered subsequently requires embroidering with greater design widths from needle to needle or from schiffli-shuttle to schiffli-shuttle, then the schiffli-shuttles must be removed from and reinserted in their individual guideways in the new configuration manually or by auxiliary means. Schiffli-shuttles which are not currently embroidering do not remain within the shuttle guideways, since this, from an embroidering point of view, is disadvantageous.
A needle repeat change system arranged on the needle side for activating and deactivating the needles according to the pattern or design to be embroidered is known from the German Pat. No. 1,952,307 which, however, cannot be used at the schiffli-shuttle side. At the needle as well at the schiffli-shuttle side, the needle threads as well the schiffli-shuttle threads are entrained loose and untied over the embroidery surface with a random length from one repeat area to the next. These loose threads, the so-called skip or jump threads, must be cut off and removed in a separate operation after the embroidered article has been removed from the machine, either by hand or by means of a special machine (Scherle machine). This causes additional retouching costs and an unnecessary waste of thread or yarn.
Concerning the state of the art, the following patents are considered relevant: Austrian Pat. Nos. 314,955; 308,513; 316,290; German Pat. Nos. 279,660; 593,838; and 1,925,301.